Recovery of metal ion resources from waste lithium batteries by in situ electro-leaching coupled with electrochemically switched ion exchange.

A new green pathway of in situ electro-leaching coupled with electrochemically switched ion exchange (EL-ESIX) technology was developed for the separation and recovery of valuable metal ions from waste lithium batteries. By using the in situ electro-leaching, the leaching rates of Li+ and Co2+ from the prepared LiCoO2 film electrodes reached 100 % and 93.30 %, respectively, under the combined effect of the acidic microenvironment formed by the anodic electrolytic water and electrostatic repulsion. Subsequently, the Li+ in the electrolyte was further extracted by an electrochemically switched ion exchange (ESIX) process using LiMn2O4 as the film electrode, and Li+ was further enriched in the eluate by a cyclic adsorption and desorption process. The results indicate that the in situ electro-leaching has significant advantages over powder leaching, and for the recycling of waste lithium batteries, the final lithium recovery rate reached 94.51 % by using this in situ EL-ESIX technology.

Removal of high concentration of chloride ions by electrocoagulation using aluminium electrode.

Wastewater containing a high concentration of chloride ions (Cl- ions) generated in industrial production will corrode equipment and pipelines and cause environmental problems. At present, systematic research on Cl- removal by electrocoagulation is scarce. To study the Cl- removal mechanism, process parameters (current density and plate spacing), and the influence of coexisting ions on the removal of Cl- in electrocoagulation, we use aluminum (Al) as the sacrificial anode, combined with physical characterization and density functional theory (DFT) to study Cl- removal by electrocoagulation. The result showed that the use of electrocoagulation technology to remove Cl- can reduce the concentration of Cl- in an aqueous solution below 250 ppm, meeting the Cl- emission standard. The mechanism of Cl- removal is mainly co-precipitation and electrostatic adsorption by forming chlorine-containing metal hydroxyl complexes. The current density and plate spacing affect the Cl- removal effect and operation cost. As a coexisting cation, magnesium ion (Mg2+) promotes the removal of Cl-, while calcium ion (Ca2+) inhibits it. Fluoride ion (F-), sulfate (SO42-), and nitrate (NO3-) as coexisting anions affect the removal of Cl- ions through competitive reaction. This work provides a theoretical basis for the industrialization of Cl- removal by electrocoagulation.

Nanosheet-state cobalt-manganese oxide with multifarious active regions derived from oxidation-etching of metal organic framework precursor for catalytic combustion of toluene.

For the first time, a nanosheet-state CoMnx mixed oxide with multifarious active regions was synthesized by oxidation-etching assembly of metal organic framework (MOF) precursor and applied for catalytic combustion of toluene at low temperatures. The obtained optimum catalyst denoted as CoMn6 showed excellent performance, which achieved 90% conversion of 1,000 ppm toluene under a weight hourly space velocity (WHSV) of 60,000 mL/(g·h) at 219 °C. While, it also exhibited long-term stability with strong water resistance property. The characterizations of physicochemical properties indicated that the oxidation-etching assembly process built an abundant mesoporous structure in the CoMnx catalyst, which greatly increased the specific surface area (SSA). Especially, potassium permanganate as oxidant and manganese source led to uniform dispersion and assembling of cobalt atoms, which caused the generation of low-crystallinity CoMnx mixed oxide with abundant dislocations, vacancies, phase interfaces and amorphous structures, resulting in excellent low-temperature reducibility, outstanding lattice oxygen mobility and abundant active species such as Mn3+, Co3+ and adsorbed oxygen species. Density functional theory (DFT) calculations demonstrated that gaseous oxygen with the longer bond length (1.406 Å) and stronger adsorption energy (-4.443 eV) could be adsorbed and activated well on the MnCo2O4.5 (311) plane, which is beneficial for the toluene oxidation. In situ diffuse reflectance infrared spectroscopy (DRIFTS) technique was applied to track the intermediates of toluene combustion under different atmospheres, which further deduced the contributions of different active regions and oxidation mechanism over the CoMnx catalyst. The present facile strategy of oxidation-etching assembly of the MOF precursor for the creating of novel catalyst with high performance could be applied in a wide variety of materials besides VOC combustion catalysts.

Generation of Abundant Defects in Ferrite Carbon Magnetic Nanomaterials for Eliminating Electromagnetic Interference in Communication.

A series of novel ferrite carbon nanomaterials are considered to obtain the potential advantages in elimination of the electromagnetic interference effects. Herein, the iron nanoparticles coated on amorphous carbon were prepared by facile agar-gel synthesis. Meanwhile, the synergy between carbon supporting and ferrite nanomaterials could be proved to promote the absorption properties. Among all samples, the iron nanoparticles coated on amorphous carbon show the highest microwave absorption properties, achieving the maximum reflection loss (RL) of -14.3 dB at 6 GHz (5.5-milimeter thickness), and the bandwidths over -10 dB (90% absorption) was 2.5 GHz. Combining analysis results, it is confirmed that the as-prepared iron nanoparticles have the highest surface area, homogeneous distribution, abundant defect, and well-defined pore structure, which could significantly affect the absorption properties at 6 GHz. Furthermore, the abundant defects derived from the interface were the essential reason for the improved absorption properties. Overall, it provided a new strategy to design an effective method to absorb nanomaterials for the elimination of electromagnetic interference, especially the coordination of metal species and carbon supporting.

Trace holmium assisting delaminated OMS-2 catalysts for total toluene oxidation at low temperature.

In this study, octahedral molecular sieve (OMS-2) is successfully delaminated by using trace holmium (Ho) via a facile redox co-precipitation route, which exhibits high performance for the total toluene oxidation at low temperature. High resolution transmission electron microscope (HRTEM), X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) analyses verify that abundant multi-phase interfaces and lattice dislocations are formed on the obtained delaminated OMS-2 by the Ho (Ho-OMS-2), which can induce more active oxygen species. In particular, the delaminated OMS-2 with a trace Ho amount has a high Oads/Olatt ratio with a balanced ratio of Mn3+ and Mn4+, demonstrating much higher activity (T100% of 228 °C even under 5 vol% H2O vapor over 0.5% Ho-OMS-2) than the parent OMS-2 (T100% of 261 °C) for the total toluene oxidation. Furthermore, the positive effect of the introduction of H2O on catalytic activity, especially the enhancement of the conversion of intermediates into CO2 and H2O, is verified by the in situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS). Based on these results, the reaction mechanism for toluene oxidation over the OMS-2 based catalyst is proposed. It is expected to provide an effective preparation method to obtain high-performance catalysts for the VOCs oxidation at low temperatures.

Microwave-assisted synthesis of manganese oxide catalysts for total toluene oxidation.

Oxygen vacancy on the heterogeneous catalyst is of great importance to the catalysis of volatile organic compound (VOC) oxidation. Herein, microwave radiation with special energy-excitation is successfully utilized for the post-processing of a series of manganese oxides (MnOx) to generate oxygen vacancies. It is found that the MnOx catalyst with 60 min of microwave radiation demonstrates higher activity for toluene oxidation with a T50% of 210 °C and a T100% of 223 °C, which is attributed to the higher concentration of oxygen vacancies derived from the rich phase interface defects resulted from the microwave radiation. Furthermore, the Mn-MW-60 catalyst possesses excellent thermal stability and water vapor tolerance even under 20 vol% H2O atmospheres within 60 h. In situ DRIFTS analysis verifies that both surface and lattice oxygen species simultaneously participate the oxidation process, and all reactions over different environments follows two different pathways. Meanwhile, it is proposed that those oxygen vacancies derived from microwave radiation could facilitate the rate-controlling step of opening the aromatic ring based on the electron back-donation, thereby leading to the increment of catalytic activity.

Biomass-Derived N-Doped Carbon for Efficient Electrocatalytic CO2 Reduction to CO and Zn-CO2 Batteries.

Conversion of CO2 into valuable chemicals via electrochemical CO2 reduction reaction (CO2RR) is a promising technology to alleviate the energy crisis and the greenhouse effect. Herein, low-cost wood biomass was applied as the carbon source to prepare nitrogen (N)-doped carbon electrocatalysts for the conversion of CO2 to CO and further as the cathode material for Zn-CO2 batteries. By virtue of N-doping and assistance of FeCl3, a cedar biomass-derived three-dimensional (3D) N-doped graphitized carbon with a high N-doping content (5.38%), an ultrahigh specific surface area (1673.6 m2 g-1), rich nanopores, and sufficient active N sites was successfully obtained, which exhibited super CO2RR activity with a high faradaic efficiency of 91% at a low applied potential of 0.56 V (vs RHE) and a long-term stability for at least 20 h. Furthermore, a Zn-CO2 battery with it as the cathode material delivered a stable open circuit voltage of 0.79 V, a peak power density of 0.51 mW cm-2 at 2.14 mA cm-2, and a maximum faradaic efficiency to CO of 80.4% at 2.56 mA cm-2, indicating that it could be applied in a practical process by using CO2 to generate power with the production of CO. Density functional theory calculations revealed that pyridinic N could more effectively decrease the free energy barriers for CO2RR and boost the reaction. This work not only revealed a facile approach to convert waste biomass into N-doped-graphitization carbon as valuable CO2RR electrocatalysts but also provided a new strategy to achieve "carbon solving carbon's problem".

Electroactive magnetic microparticles for the selective elimination of cesium ions in the wastewater.

To improve operability as well as the removal efficiency for cesium ions in the wastewater treatment, a novel electrochemically switched ion exchange (ESIX) technique by using electroactive Prussian-blue(PB)-based magnetic microparticles (PB@Fe3O4 microparticle) with different uniform particle sizes in the range of 300-900 nm as the adsorption materials was developed. The obtained PB@Fe3O4 microparticle were characterized by Scanning electron microscopy (SEM), Transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and Thermogravimetric analysis (TGA). It is found that the PB can be well coated on the surface of Fe3O4 microsphere, which can be easily adsorbed on the magnetic electrode substrate for the electrochemical adsorption of Cs+ ions. Electrochemical adsorption of 97% Cs+ on PB/Fe3O4 was achieved in less than 10 min, and the maximum adsorption capacity was 16.13 mg/g, and the distribution coefficient (KD) of Cs+ ions reached as high as 3938. In addition, the electrochemical adsorption behavior of PB@Fe3O4 microparticle fitted well with the Freundlich adsorption isotherm and the Pseudo-second-order kinetic models. It is expected that such an ESIX technique using PB@Fe3O4 microparticle can be applied for the separation and recovery of dilute Cs+ ions from cesium-contaminated solution in a practical process.

Theoretical and experimental investigations of the electronic/ionic conductivity and deprotonation of Ni3-xCoxAl-LDHs in an electrochemical energy storage system.

The remarkable effect of divalent transition metal ions on the electrochemical performance of transition metal-based layered double hydroxides (LDHs) was systematically investigated via computational and experimental approaches. Ni3-xCoxAl-LDHs (x = 0, 1, 2, and 3) were synthesized on carbon paper by a unipolar pulse electrodeposition (UPED) method and used as electrodes in energy storage systems. The structures were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Their electrochemical performance was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The mechanism of different electrochemical performances with various divalent transition metal ions was investigated by the density functional theory (DFT) plus U method and molecular dynamics (MD) simulations. The computational and experimental data demonstrated that the electronic and ionic conductivity and deprotonation of NiAl-LDHs were improved by doping Co species, and the incorporation of Co and Ni cations enabled LDHs to exhibit a larger interlayer spacing which can facilitate the diffusion of OH- ions, indicating that NiCo2Al-LDHs had the highest specific capacitance.

Incidence of extended-spectrum beta-lactamases and characterization of integrons in extended-spectrum beta-lactamase-producing Klebsiella pneumoniae isolated in Shantou, China.

This study is concerned with the level of antibiotic resistance of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae, isolated in Shantou, China, and its mechanism. Seventy-four non-repetitive clinical isolates of K. pneumoniae producing ESBLs were isolated over a period of 2 years. Antibiotic susceptibility, carried out by Epsilometer test, showed that most of the isolates were multiresistant. Polymerase chain reaction showed that, among the several types of beta-lactamases, SHV was the most prevalent, TEM was the second most prevalent, and CTX-M was the least prevalent. Sixty-nine isolates were positive for integrase gene IntI1, but no IntI2 or IntI3 genes were found. The variable region of class 1 integrons were amplified and further identified by sequencing. Thirteen different gene cassettes and 11 different cassette combinations were detected. Dfr and aadA cassettes were predominant and cassette combinations dfrA12, orfF and aadA2 were most frequently found. No gene cassettes encoding ESBLs were found. Integrons were prevalent and played an important role in multidrug resistance in ESBL-producing K. pneumoniae.

Disruption of glial function enhances electroacupuncture analgesia in arthritic rats.

Activated glia play a major role in mediating behavioral hypersensitive state following peripheral inflammation. Electroacupuncture is well known to relieve persistent inflammatory pain. The present study was undertaken to examine whether fluorocitrate, a glial metabolic inhibitor, could synergize electroacupuncture antagonizing thermal hyperalgesia and mechanical allodynia evoked by ankle joint inflammation. Monoarthritis of rat ankle joint was induced by an intra-articular injection of Complete Freund's Adjuvant (CFA). The paw withdrawal latency (PWL) from a thermal stimulus and paw withdrawal threshold (PWT) from von Frey hairs were measured in awake rats. Intrathecal (i.t.) injection of 1 nmol fluorocitrate markedly suppressed monoarthritis-induced thermal hyperalgesia and mechanical allodynia. Unilateral electroacupuncture stimulation of "Huantiao" (GB30) and "Yanglingquan" (GB34) acupuncture points (100/2 Hz alternation, 1-2-3 mA) significantly elevated the PWLs and PWTs for 45 min after cessation of electroacupuncture in monoarthritic rats. Co-application of 0.1 or 1 nmol fluorocitrate with electroacupuncture significantly potentiated electroacupuncture analgesia, although 0.1 nmol fluorocitrate alone had no effect on PWLs and PWTs in monoarthritic rats. These results suggested that electroacupuncture and disrupting glial function could synergistically antagonize inflammatory pain, which might provide a potential strategy for the treatment of arthritic pain.

Is endogenous D-serine in the rostral anterior cingulate cortex necessary for pain-related negative affect?

Functional activation of NMDA receptors requires co-activation of glutamate- and glycine-binding sites. D-serine is considered to be an endogenous ligand for the glycine site of NMDA receptors. Using a combination of a rat formalin-induced conditioned place avoidance (F-CPA) behavioral model and whole-cell patch-clamp recording in rostral anterior cingulate cortex (rACC) slices, we examined the effects of d-amino acid oxidase (DAAO), an endogenous D-serine-degrading enzyme, and 7-chlorokynurenate (7Cl-KYNA), an antagonist of the glycine site of NMDA receptors, on pain-related aversion. Degradation of endogenous D-serine with DAAO, or selective blockade of the glycine site of NMDA receptors by 7Cl-KYNA, effectively inhibited NMDA-evoked currents in rACC slices. Intra-rACC injection of DAAO (0.1 U) and 7Cl-KYNA (2 and 0.2 mM, 0.6 microL per side) 20 min before F-CPA conditioning greatly attenuated F-CPA scores, but did not affect formalin-induced acute nociceptive behaviors and electric foot shock-induced conditioned place avoidance. This study reveals for the first time that endogenous D-serine plays a critical role in pain-related aversion by activating the glycine site of NMDA receptors in the rACC. Furthermore, these results extend our hypothesis that activation of NMDA receptors in the rACC is necessary for the acquisition of specific pain-related negative emotion. Thus a new and promising strategy for the prevention of chronic pain-induced emotional disturbance might be raised.

Antinociceptive effects of meptazinol and its isomers on carrageenan-induced thermal hyperalgesia in rats.

Using the latency of paw withdrawal (PWL) from a noxious thermal stimulus as a measure of hyperalgesia, the effects of i.p. injection of meptazinol and its isomers, 112824 and 112825, on carrageenan-induced thermal hyperalgesia were studied in awaked carrageenan-inflamed rats. Peripheral inflammation was induced by intraplantar (i.pl.) injection of carrageenan (2 mg/100 microl) into one hindpaw in rats. Carrageenan produced marked inflammation (edema and erythema) and thermal hyperalgesia in the injected paws, which peaked at 3 h after injection and showed little change in magnitude for another 3 h. Injection of 0.1 mg/kg meptazinol (i.p.) at 3 h after carrageenan had no effect on the PWLs of either inflamed or non-inflamed hindpaw during the next 100 min (P>0.05, n=8). At the dosage of 1 and 10 mg/kg, meptazinol produced marked anti-nociception and anti-hyperalgesia in non-inflamed and inflamed hindpaw, respectively (P<0.05, n=8-11). The prolonging effect of meptazinol on PWL in inflamed hindpaw was more potent than that in non-inflamed hindpaw. Pre-administration of 1.5 mg/kg naloxone significantly antagonized meptazinol-induced anti-nociception and anti-hyperalgesia. Intraperitoneal injection of an isomer of meptazinol, 112825 (1.5 mg/kg), but not 112824 (1 mg/kg), markedly increased the PWL of the non-inflamed hindpaw. Nevertheless, both the isomers produced similar anti-hyperalgesic effect to that of meptazinol (P<0.05, n=8), which was completely reversed by naloxone (1.5 mg/mg). The results suggest that meptazinol and its isomers have anti-nociceptive and anti-hyperalgesic properties with the former more potent. The effects are mainly mediated by mu opioid receptors. This study provides an important clue for extending clinical utilization of meptazinol and its isomers.